METHOD FOR INSTALLING UNDERFLOOR STRUCTURES

PROBLEM TO BE SOLVED: To provide a method for installing underfloor structures, capable of shortening a period required for constructing the underfloor structures such as island foundations, base boards, and cable storage bodies and shortening a construction period of a building.SOLUTION: In a method for constructing underfloor structures to install island foundations 5 and board bases 4 for supporting boards 1 installed on a floor surface, and cable storage bodies 3 under a floor, a block 13a previously integrated before an installation process thereof is used as a plurality of the island foundations 5, the board bases 4, and the cable storage bodies 3. The installation process includes: a step for suspending the block 13a by a suspending jig 9 and installing it on a floor bottom surface portion 8; and a step for placing concrete on the floor bottom surface portion 8 while suspending the block 13a. Moreover, in the installation process, some of the island foundations 5 are supported via support frames 10 arranged on the floor bottom surface portion 8 while suspending the island foundations 5 of the block 13a by the suspending jig 9, and in this state, the concrete is placed on the floor bottom surface portion 8.